This invention relates to door locks for a vehicle, and particularly locks with electrical locking and unlocking.
This type of lock comprises a forked latch bolt in a known manner designed to cooperate with a striker, a pawl that normally holds the latch bolt in the closed position, a latch bolt release mechanism comprising a control device to which an actuating movement is applied when the user operates the corresponding vehicle door handle. The control device may be in an active position during which it acts on the pawl during actuating movement to put the pawl in a xe2x80x9cretractedxe2x80x9d position (in which said pawl frees the latch bolt), and an inactive position in which said control device has no effect on said pawl during its actuating movement. The lock also comprises an electromechanical locking/unlocking system that responds to at least one unlocking signal by moving said control device from its inactive position to its active position.
Vehicle door closing systems are known in which the unlocking signal is generated by activating a lock barrel. In other known systems, this unlocking signal is generated by an electronic recognition device in response to an infrared remote control signal or a radio-electric remote control signal produced by the user operating an appropriate remote control. With these known systems, if the lock is in the locked state, in other words if the control device that forms part of the latch bolt release mechanism is in its inactive position, two successive actions are then necessary to open the door; first, the lock needs to be released using appropriate means (key, remote control, etc.), and then the door has to be opened, for example by pulling on its outside handle.
Obviously, when the vehicle is used frequently, it is inconvenient to be obliged always to carry out two actions to unlock then unfasten the door in order to enter the vehicle. Furthermore, this could also be seen as a nuisance to the extent that these known systems require the use of either a key or a remote control which occupies one of the user""s hands.
This is why so-called xe2x80x9chands-off accessxe2x80x9d systems have already been proposed, designed to enable a user to open a vehicle door directly by a single action on the outside handle of the corresponding door, regardless of whether said door lock is in the locked or unlocked state, without the need for a key, remote control or any similar device in order to unlock the door. In these known systems, this is done by the use of an electronic recognition device equipped with a radio transmitter designed to communicate with a radio-electric device called an xe2x80x9celectronic identifierxe2x80x9d, built into a watch, credit card, badge or similar device worn or carried by the user. The electronic recognition device does not produce its unlocking signal until the right owner has been identified.
In this type of known xe2x80x9chands-off accessxe2x80x9d system, an unlocking signal controlling the electromechanical locking/unlocking device is emitted at the same time as the release mechanism is actuated. The difference between the relatively long response time of the electromechanical device and the relatively short response time of the release mechanism is such that said control device which forms part of the latch bolt release mechanism has frequently terminated its activation movement although the electromechanical locking/unlocking device has still not put the control device in the active position. The result is that the first time that the user operates the door handle does not open the door, and he must operate the door handle again to open the door. The fact that the door handle has to be pressed twice is obviously a disadvantage for a system which is intended to open the door in a single operation.
French patent application No. 98 05604 submitted on May 4, 1998 provides two solutions for overcoming this disadvantage. These two solutions consist of using an opening compensation means which brings the pawl into its xe2x80x9cretractedxe2x80x9d position, if an unlocking signal is sent substantially at the end of the control device actuating movement. Specifically, in both of these two known solutions, the control device that acts on the pawl to move it into its xe2x80x9cretractedxe2x80x9d position or an actuation lever which also forms part of the latch bolt release mechanism, is shaped so that part of its surface is in the shape of a ramp at an angle to the direction of movement of the control device. At the end of the movement actuating said control device, the shaped part acts directly or indirectly depending on solution mentioned above, like a cam on the pawl to move it into its xe2x80x9cretractedxe2x80x9d position.
The purpose of this invention is to provide a solution that avoids the need for the user to exert two actions on the door handle in order to open it.
Consequently, the invention relates to an electrical locking/unlocking lock for a vehicle door, with hands-off access, comprising:
a) a forked latch bolt which cooperates with a striker,
b) a pawl that blocks the latch bolt in the closed position and which can be moved into a xe2x80x9cretractedxe2x80x9d position in which it no longer acts on the latch bolt,
c) a latch bolt release mechanism comprising a control device which may be actuated in response to a user operating said door handle and which, in the unlocked state of the lock, can act on the pawl during its actuating movement to bring it into said xe2x80x9cretractedxe2x80x9d position,
d) an electromechanical locking/unlocking device including an electric actuating device that reacts to at least one unlocking signal to put the lock into said unlocked state,
e) an electronic recognition device capable of producing said unlocking signal when it recognizes an appropriate electronic identifying device worn or carried by the vehicle owner or by an authorized user;
and an electromechanical latch bolt release device comprising another electric actuating device that reacts to said unlocking signal by acting directly on the pawl or on a part associated with the pawl, which is distinct from the parts of said release mechanism and said electromechanical locking/unlocking device, to put said pawl into its xe2x80x9cretractedxe2x80x9d position.
Under these conditions, given that two distinct electric drive devices are provided, a first electric drive device for locking/unlocking the lock and a second electric drive device to release the latch bolt, both of which react to the unlocking signal, the first electric actuating device, composed for example of an electromagnet or an electric motor, may be small and of low power since all it has to do is bring the pawl into its xe2x80x9cretractedxe2x80x9d position to release the latch bolt. The second electric actuating device, which for example may be composed of an electric motor associated with a set of reduction gears, may also be compact and of low power since it no longer needs to unlock the lock and release the latch bolt, but simply has to release the latch bolt by putting the pawl into its xe2x80x9cretractedxe2x80x9d position. Note also that if there is a mechanical and/or electrical failure of the electromechanical locking/unlocking device or its electrical actuating device, even if the lock remained in a locked state, the latch bolt can still be released and the vehicle door may be opened using the electronic recognition device and the second electrical actuating device that acts directly on the lock pawl to put the lock pawl into its xe2x80x9cretractedxe2x80x9d position without using the normal movement control systems in the release mechanism and/or the electromechanical locking/unlocking device.
Preferably, according to one possible embodiment of the invention, the electromechanical release device comprises an electric motor that acts on a drive which acts in turn on the pawl to put it into the xe2x80x9cretractedxe2x80x9d position in response to the unlocking signal.
The electrical power supply for the motor may pass through a normally open switch, which is closed in response to a transmitted unlocking signal, this switch closing an electric power supply circuit to the motor.
Preferably, the electronic recognition device only receives an electric power supply when the user exerts an opening action on the door handle. This thus avoids the electronic recognition device being permanently powered and pointlessly consuming energy.
Consequently, the electrical power supply to the electronic recognition device may be applied by a control system such as a normally open microswitch, which is closed under the control of said opening action exerted on the door handle. This microswitch closes an electric power supply circuit to the electronic recognition device.